HAVANA (AP) – Tropical Storm Ernesto hit Cuba west of the U.S. naval air base at Guantanamo Bay on Monday after killing one person in Haiti as it stayed on track toward Florida, where forecasters expect it to strengthen back into a hurricane.

Ernesto became the Atlantic season’s first hurricane on Sunday morning with maximum sustained winds of about 75 mph before weakening and moving ashore about 20 miles west of Guantanamo, with top sustained winds of nearly 40 mph _ that’s 1 mph above the minimum to be a tropical storm.

Forecasters said Ernesto would regain strength once it reached the warm waters north of Cuba, and Florida Gov. Jeb Bush declared an emergency, ordering tourists to evacuate the Florida Keys.

“We do expect it to reach the Gulf, maybe as a Category 1 hurricane, possibly a Category 2,” said John Cangialosi, a meteorologist with U.S. National Hurricane Center in Miami. “It’s difficult to say where it will be, but in three days we’re projecting it anywhere from the eastern Gulf near the Florida panhandle to the western Bahamas.”

About 400 miles of the Florida coast were under a hurricane watch from New Smyrna Beach southward on the east coast and from Chokoloskee southward on the west coast. The Keys were put under a watch Sunday.

“I don’t want anyone to overly focus on the downgrading. … It has a good chance to regain hurricane status,” said Max Mayfield, director of the hurricane center.

NASA gave up on a Tuesday space shuttle launch and prepared to move Atlantis into its giant shelter at Cape Canaveral, Fla., if the storm continued to threaten.

Bush urged Florida residents to make preparations and not wait until the storm is upgraded. It’s a familiar theme, considering seven hurricanes have hit Florida and one has brushed by in the past two years.

“My suggestion: Take this storm very seriously. A hurricane is a hurricane,” said Bush, urging people to have 72 hours worth of supplies.

At 2 p.m. EDT, Ernesto’s poorly defined center was about 15 miles east-southeast of Holguin, Cuba, moving northwest near 10 mph. It dumped heavy rain in localized areas of eastern Cuba, but the storm’s winds had diminished greatly as it started moving across land, leading Cuban meteorologist Jose Rubiera said on state television.

None of the 445 prisoners being held at the U.S. base at Guantanamo because of suspected of links to al-Qaida or the Taliban were exposed to the weather. For the last three years, detainees have been kept in cells without windows or with a single window covered with a heavy steel hurricane shutter. The cells replaced the open steel cages where prisoners were initially held.

U.S. military personnel, except for guards and people in other critical jobs, were told to stay in their quarters until the storm passed, said Navy Lt. Cmdr. Jeffrey Gordon, a Defense Department spokesman.

There were no reports of damage or injury in Cuba. The communist government regularly undertakes mass evacuations before tropical storms and hurricanes to minimize injury and loss of life. This time, Cubans moved cattle to higher ground, tourists were evacuated from hotels in the southeastern province of Granma and baseball games were rescheduled for earlier in the day in Havana. Train service across the country was also stopped while the storm passes.

The government changed a hurricane warning for six eastern provinces in Cuba to a tropical storm warning, and state TV urged precautions. Cattle were moved to higher ground, tourists were evacuated from hotels in the southeastern province of Granma, and baseball games scheduled for Sunday night in Havana were played earlier in the day.

The storm could return to open ocean north of Cuba as early as Monday night, Rubiera said.

A hurricane watch also was posted for the northwestern Bahamas and a tropical storm warning was issued for the central Bahamas.

Cruise ship companies said they were diverting several liners to avoid the storm.

In Haiti, Marie Alta Jean-Baptiste, director of the civil protection agency, said one person on Vache island off Haiti’s south coast died in the storm, but she could not give details.

Skies darkened as wind gusts swayed palm trees in Les Cayes, 100 miles west of the capital of Port-au-Prince. People put goats and cows into shelters, and fishermen pulled nets ashore.

Forecasters said up to 20 inches of rain could fall in some mountain areas of Haiti, raising fears of flash floods in the heavily deforested country.

“The only thing we can do is just wait and keep our fingers crossed,” said Frantz Gregoire, 42, owner of the Bay Club, a thatch-roofed seaside restaurant. He said he would send his workers home if the storm worsened.

Haitian officials went on the radio to warn people in coastal shantytowns to seek shelter in schools and churches and they evacuated some low-lying areas in the northwestern city of Gonaives, which was devastated by floods during Tropical Storm Jeanne in 2004.